That's a good point! And actually, I guess, knowing Brust and the way he likes playing with time strands in his books, it's just as likely that the present-day relationship between Vlad and Cawti would be in that book (i.e. Tsalmoth) itself... I figured a book set between Yendi and Jhereg would have to focus on Vlad and Cawti, but hadn't thought of it in terms of illuminating their present-day relationship / moving that strand forward, but that would make a lot of sense.